The aim of this research program is to isolate the proteins involved in DNA replication in E.Coli. We have isolated twenty-five fractions which stimulate ATP dependent DNA synthesis in vitro. We have also isolated the bacterial nucleoid and added to it our protein fractions and have observed ATP dependent DNA synthesis. The pieces of DNA made are very small, i.e., about 3 S. The major effort of our research will now be to purify our crude fractions to try to find the minimum number of proteins required for DNA replication.